Prior to a4330302f22d ("libcompat: build 32-bit rtld and ldd as part of
"everything""), ldd32 and ld-elf32.so.1 were build by Makefile.libcompat
and thus were put into the lib32 distribution. However, when they were
moved to being built during everything, bsd.compat.mk never learned to
set DISTRIBUTION accordingly, and so they moved from lib32 to base. Fix
this by setting the default to restore the old behaviour.
Fixes: a4330302f22d ("libcompat: build 32-bit rtld and ldd as part of "everything"")